It says for CottonOn & Co. Perks members but link is accessible to anyone. Just in case you wanna be member and also get $10 signup voucher (minimum spend $25) deal is here
Shipster: Free shipping applies to orders from participating retailers with an order total of $25 and over and shipping costs under $20. Domestic parcels only.
Terms and conditions
*This promotional offer is available to CottonOn & Co. Perks members only. The promotional offer entitles eligible CottonOn & Co. Perks members to 12 months free Shipster subscription from the date of email confirmation of subscription to Shipster from Australia Post. No payment details are taken at the time of initial sign up to Shipster. At the end of the 12 months, an email will be sent to you inviting you to renew your membership at the regular pricing and terms. See auspost.com.au/shipster for more information.
By agreeing to the offer, you also agree to the Shipster terms and conditions which can be viewed at auspost.com.au/shipster.
The promotional offer and the 12 month free subscription is concurrent with any existing offer of promotion for free subscription to Shipster.
Offer is available from Friday 8 June 2018 to 11.59pm Monday 11 June 2018.
Offer is available from Tuesday 19 June 2018 to 11.59pm Friday 22 June 2018.